Electric machines are generally comprised of a stator assembly and a rotor assembly. During operation of the electric machines, a considerable amount of heat energy can be generated by both the stator assembly and the rotor assembly, in addition to other components of the electric machines. Conventional cooling methods can include removing the generated heat energy by convection to a jacket filled with a coolant.
Limitations associated with some electric machines can include difficulties associated with designing insulation for some portions of the stator assembly, however, difficulties also can arise in cooling of the rotor assembly. Also, some electric machines, including interior permanent magnet electric machines, can include magnets, which can generate heat energy but can be difficult to cool. If not properly cooled, the magnets can become largely demagnetized which can lead to a decrease in electric machine productivity and lifespan.